scholarly journals An investigation of a detection method for a subsurface crack in the outer race of a cylindrical roller bearing

2017 ◽  
Vol 19 (2) ◽  
pp. 211-219 ◽  
Author(s):  
Jing Liu ◽  
Zhifeng Shi ◽  
Yimin Shao
Keyword(s):  
Detection Method ◽  
Roller Bearing ◽  
Subsurface Crack ◽  
Outer Race ◽  
Cylindrical Roller Bearing ◽  
Cylindrical Roller

Influence of roller defect and coupled roller–inner–outer race defects on the performance of cylindrical roller bearing

2019 ◽  
Vol 233 (3) ◽  
pp. 731-746 ◽  
Author(s):  
Sachin P Patel ◽  
S H Upadhyay
Keyword(s):  
Nonlinear Equations ◽  
Normal Load ◽  
Roller Bearing ◽  
Surface Irregularity ◽  
Outer Race ◽  
Cylindrical Roller Bearing ◽  
The Time Domain ◽  
Internal Gap ◽  
Thrust Load ◽  
Cylindrical Roller

In the present study, a novel mathematical model is developed for the deformation between roller and races of cylindrical roller bearing using the effect of tilting and skewing of roller due to thrust load, radial deflection due to normal load, radial internal gap, and individual defect on roller as well as coupled defect on all races and roller. Also, novel roller defect function is proposed for the preparation of simultaneous nonlinear equations. MATLAB is used to solve nonlinear equations for equilibrium conditions of deflection, radial load, thrust load, moment in plane, and total roller loading. However, waviness due to surface irregularity on both races as well as out-of-balance assembly is not considered in this analysis. The bearing is analyzed for individual roller defect as well as coupled races–roller defects to identify the behavior of bearing under speed-varying conditions. The equation of motion is solved through Newmark-β technique. Defect segment of roller consecutively in contact with both races results in higher acceleration. Time-to-impact concept is utilized for the analysis. The acceleration during roller–race defect interaction with intermittent connection is applied in the model for observation. The outcomes are shown in the time domain, orbit, and envelope analysis, which describe the complexity of the system with speed variation for roller defect and coupled roller–inner–outer race defects. The periodic, quasi-periodic, and chaotic phenomena are observed for roller and coupled defects. Simulated frequencies for all defects are compared with theoretical frequencies to validate the model.

Nonlinear analysis of cylindrical roller bearing under the influence of defect on individual and coupled inner–outer race

2018 ◽  
Vol 233 (2) ◽  
pp. 404-428 ◽  
Author(s):  
Sachin P Patel ◽  
S H Upadhyay
Keyword(s):  
Mathematical Model ◽  
Axial Load ◽  
Roller Bearing ◽  
Equation Of Motion ◽  
Radial Clearance ◽  
Normal Loading ◽  
Peak Displacement ◽  
Outer Race ◽  
Cylindrical Roller Bearing ◽  
Cylindrical Roller

In this paper, new mathematical model has been developed for the cylindrical roller bearing by considering coupled influence of radial deflection due to normal loading, roller titling, roller skewing, radial clearance, and also individual as well as coupled inner and outer race defects. Novel defect function is also developed for inner and outer race defects based on literature, to make a set of nonlinear equations for mathematical model, which are solved by using MATLAB. Newmark-β method is applied to solve the equation of motion. The results are plotted in time domain, velocity-displacement, and envelope analysis. The obtained results show the sensitiveness of the system with the variations in speed for the inner, outer, and combined inner–outer race defects. The peak displacement, velocity, and acceleration have been observed for various defects which are helpful to obtain the system’s dynamic behavior under speed varying condition for combined radial and axial load. A major finding of this paper is regarding the understanding of the system’s behavior like periodic to chaotic under varying speed conditions with the attention of individual and coupled inner and outer race defects with the inclusion of normal loading, tilting, skewing, and radial clearance effect and validation of simulated results with the calculated one.

scholarly journals Calculated and Experimental Data for a 118-mm Bore Roller Bearing to 3 Million DN

1981 ◽  
Vol 103 (2) ◽  
pp. 274-281 ◽  
Author(s):  
H. H. Coe ◽  
F. T. Schuller
Keyword(s):  
Experimental Data ◽  
Computer Program ◽  
Roller Bearing ◽  
Operating Characteristics ◽  
Flow Rates ◽  
Outer Race ◽  
Lubricant Flow ◽  
Cylindrical Roller Bearing ◽  
Cylindrical Roller

Operating characteristics for a 118-mm bore cylindrical roller bearing were calculated using the computer program CYBEAN. The predicted results of inner and outer-race temperatures and heat transferred to the lubricant generally compared well with experimental data for shaft speeds to 3 million DN (25,500 rpm), radial loads to 8900 N (2000 lb), and total lubricant flow rates to 0.0102 m3/min (2.7 gal/min).

scholarly journals Dynamic Performance of a Squeeze Film Damper with a Cylindrical Roller Bearing under a Large Static Radial Loading Range

Machines ◽  
2019 ◽  
Vol 7 (1) ◽  
pp. 14 ◽  
Author(s):  
Hans Meeus ◽  
Jakob Fiszer ◽  
Gabriël Van De Velde ◽  
Björn Verrelst ◽  
Wim Desmet ◽  
...  
Keyword(s):  
Roller Bearing ◽  
Squeeze Film ◽  
Stable Operation ◽  
Large Power ◽  
Squeeze Film Damper ◽  
Depth Analysis ◽  
Rotor Support ◽  
Cylindrical Roller Bearing ◽  
Radial Loading ◽  
Cylindrical Roller

Turbomachine rotors, supported by little damped rolling element bearings, are generally sensitive to unbalance excitation. Accordingly, most machines incorporate squeeze film damper technology to dissipate mechanical energy caused by rotor vibrations and to ensure stable operation. When developing a novel geared turbomachine able to cover a large power range, a uniform mechanical drivetrain needs to perform well over the large operational loading range. Especially, the rotor support, containing a squeeze film damper and cylindrical roller bearing in series, is of vital importance in this respect. Thus, the direct objective of this research project was to map the performance of the envisioned rotor support by estimating the damping ratio based on the simulated and measured vibration response during run-up. An academic test rig was developed to provide an in-depth analysis on the key components in a more controlled setting. Both the numerical simulation and measurement results exposed severe vibration problems for an insufficiently radial loaded bearing due to a pronounced anisotropic bearing stiffness. As a result, a split first whirl mode arose with its backward component heavily triggered by the synchronous unbalance excitation. Hence, the proposed SFD does not function properly in the lower radial loading range. Increasing the static load on the bearing or providing a modified rotor support for the lower power variants will help mitigating the vibration issues.

Investigation on the drag effect of a rolling element confined in the cavity of a cylindrical roller bearing

2021 ◽  
pp. 135065012110260
Author(s):  
Wenjun Gao ◽  
Shuo Zhang ◽  
Xiaohang Li ◽  
Zhenxia Liu
Keyword(s):  
Open Space ◽  
Roller Bearing ◽  
Flow Characteristics ◽  
Experimental Tests ◽  
Windward Side ◽  
Leeward Side ◽  
Drag Effect ◽  
Rolling Element ◽  
Cylindrical Roller Bearing ◽  
Cylindrical Roller

In cylindrical roller bearings, the drag effect may be induced by the rolling element translating in a fluid environment of the bearing cavity. In this article, the computational fluid dynamics method and experimental tests are employed to analyse its flow characteristics and pressure distribution. The results indicate that the pressure difference between the windward side and the leeward side of the cylinder is raised in view of it blocking the flow field. Four whirl vortexes are formed in four outlets of two wedge-shaped areas between the front part of the cylindrical surface and adjacent walls for the cylinder of L/ D = 1.5 at Re = 4.5 × 103. Vortex shedding is found in the direction of cylinder axis at Re = 4.5 × 104. The relationship between drag coefficient and Reynolds number is illustrated, obviously higher than that of the two-dimensional cylinder in open space.

Dynamics of Rolling-Element Bearings—Part I: Cylindrical Roller Bearing Analysis

1979 ◽  
Vol 101 (3) ◽  
pp. 293-302 ◽  
Author(s):  
P. K. Gupta
Keyword(s):  
Differential Equations ◽  
Normal Force ◽  
Equations Of Motion ◽  
Roller Bearing ◽  
Rolling Element Bearings ◽  
Analytical Formulation ◽  
Rolling Element ◽  
Cylindrical Roller Bearing ◽  
Cylindrical Roller ◽  
Bearing Analysis

An analytical formulation for the roller motion in a cylindrical roller bearing is presented in terms of the classical differential equations of motion. Roller-race interaction is analyzed in detail and the resulting normal force and moment vectors are determined. Elastohydrodynamic traction models are considered in determining the roller-race tractive forces and moments. Formulation for the roller end and race flange interaction during skewing of the roller is also considered. Roller-cage interactions are assumed to be either hydrodynamic or fully metallic. Simple relationships are used to determine the churning and drag losses.

Sign in / Sign up

Export Citation Format

Share Document